Joint trimmer for plaster board and the like



June 5, 1928.

J. SCHUMACHER JOINT TRIMMER FOR PLASTER BOARD AND THE LIKE OriginalFiled Nov. 5, 1925 2 Sheets-Sheet INVENTOR. /an 56h/Weber BY 77M 4^/June 5, 192s. 1,672,098

J. SCHUMACHER JOINT TRIMMER FOR PLASTER BOARD AND THE LIKE I originalFiled Nov. 5, 1925 2 sheets-Sheet 2 IN V EN TOR.

` ATTORNEYS.

Patented June 5, 1928.

UNITED STATES PATENT.; OFFICE.

JOHN SCHUMACHER, OF LOS ANGELES, CALIFQBNIA.. i

This serves admirably to produce ailush finished surface. l

The joints often become filled with oreign matter and it is advantageousto'clean` the same, and also to enlarge thejoint crack to a uniformsize, sothat a cement orA plaster putty may be inserted therein to filland bind the, panels. This` invention relates to a device for treatingthe adjoining face margins of plaster board panels to `produce a chamferand also to clean the'joint crack. Thus,

the joint will be ready for thereception ot plaster putty, ii' sodesired, and ot tape to cover the joints. i

The primary object voi? this invention is to provide a tool adapted tobe used to dress the marginal faces and clean the 'jointat oneoperation. Another object or' this invention is to provide a-,toolhavingfaces adapted.

to be covered by. a sheet of abrasive-material 1 in such a manner. thatit may be readily re'- placed. A further object of this invention is aprovide a lstructure of the character described with-a removable bladefor cleaning the joint crack, and also for .guiding the i tool. Inaddition tothe broader objects of this invention, there are certaindetails of structure whereby a simple, compact, economical, and easilymanipulatedtool` is 0bl tained.

invention illustrated in the accompanyingI drawings, in which:

Fig. 1 is a sidev elevation of one form of tool vembodying my invention,a portion thereofbeing broken away and shown in longitudinal section;Fig. 2 is an end view of the, tool as seen .looking in the direction ofthe arrows 2'o' Fig. 1; Fig. Sis a section as seen on the line 3-3 lofFig. 1; Fig. 4 is a transverse section similar to Fig. 3 showing asection through another form of my tool having no cleaning` blade; Fig.5 is a perspective view showing the fragment of adjoining plaster boardpanels after having been dressed by my improved tool; Fig. 6

JOINT TRIMMEB Fon PLASTER BOARD AND THE mxE. l.Application inea Nvember5, 1925, serial No..e7,097. Renewed November 2s, 1927.

lisaside elevation-of another foi-mot tool embodying my invention, afragment there-` of being shown in vertical section; Fig..7

is a'section asfseen on the line 7 7 of Fig. 6; and Fig. 8is alfragmentary sectional view through yadjoining panelsshowinga chami'eredtape in position covering the joints.

Referring more particularly to Figs. 1 to 4 inclusive,- a tool is shown,which may be convenientlyv made of `stamped metal. This tool comprises abody having a back 10 to which thev abrasive is adapted to 'besecuredThegbaek has side ywalls 11 and inwardly bent Vunderhanging margins 12.1A hollow back is thereby provided. Extending upwardly from theback is a"handle poition 13 ending ina rounded hand lgrip 14.. The structure justdescribed/may bebent from a single sheet of metal, the handle having aslot to receive a locking plate 15. This plate isl securedr tothe handle.by any suitable -means such as rivets 16.4 It will be noted thattheliandle ends short of the body. andy that the locking platel extendsvbeyond the tace plate are offset to provide ledges for engaging the`walls 12 of the back. The back is extendedk to'form seats 2() which maybe disposed beneath the screws 17. .The screws when forced downwardlywill hold the vface plate in position against the underhanging walls 12of the back. Covering the face of the face plate and frictionallyclamped in position by the ledges and the walls 12 is a. strip ofabrasive materialv21. `This sheet. of material may be sand papervor thelike. It is yfoi-ced into the recess in rib 19 and held in position byai'blade 22 which .has teeth `on the lower edge-thereof.. Blade 22 isheld in the rib by means of ypins 23 which extend transversely throughthe blade andv the walls of the rib.

It is vobvious that the sheet of abrasivey material may be changedeasily. T o do this screws 17 are backed up to release the face plateyfrom the back, permitting the latter tobe removed. Pins 23 are thenremoved releasing blade 22. A .new sheet of abrasive may then beinstalled, and a new blade if desired.

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